回接筒顶部修复工具的研制与应用

随着油气勘探开发向深层、超深层进军，尾管回接固井技术应用愈发广泛。回接筒是保证回接井筒完整性的核心装置，然而尾管固井后，回接筒顶部残留水泥、过度钻塞致回接筒喇叭口受损等现象时有发生，极易导致回接密封失效，从而严重影响固井质量。针对上述难题，研制了回接筒顶部修复工具，设计了磨铣回接筒的管柱组合，形成了配套修复工艺，开展了大规模地面性能测试与现场试验。研究结果表明：顶部修复工具对于清除回接筒残留水泥、修复回接筒喇叭口破损具有良好的效果，现场应用3井次，试验成功率100%,显著提高了尾管回接作业的可靠性，具有良好的应用推广前景。

Development and Application of Top Repair Casing Tool for Liner Tieback

With the development of oil and gas exploration and development into deep and ultra-deep areas,liner tieback cementing technology is increasingly widely used,and tieback barrel is the core device to ensure the integrity of tieback wellbore. However,after liner cementing,the residual cement at the top of tie-in cylinder and the damage to the horn of tie-in cylinder caused by excessive drilling-plug often occur,which can easily lead to tie-in seal failure and seriously affect the cementing quality. In view of the above problems,the top repair nipple of tieback cylinder was developed,and the string combination of milling tie-back cylinder was designed. A matching repair process was formed,and large-scale ground performance test and field test were carried out. The research results show that the top repair sub has a good effect on removing residual cement of tie-back cylinder and repairing the broken flared mouth of tie-back cylinder. It has been applied in field for 3 Wells,and the success rate of the test is 100% ,which significantly improves the reliability of tie-back operation of liner and has a good prospect of application and promotion.